Energy gels help replenish your depleted carbohydrate stores when running, giving you an extra boost during long-distance running challenges. 

When you run, your body uses two fuel sources to feed your muscles: fat and carbohydrates. While fat is widely available, it takes longer to break down into useful energy, proving ineffective when running longer distances, like during a marathon.

Instead, your body relies on carbohydrates as its primary fuel source. As a rule, the faster you run, the more fuel comes from carbohydrate intake. But, your body can only store a limited amount of carbohydrates in the muscles. This type of carbohydrate is known as glycogen.

Your glycogen stores begin to deplete at a half-marathon pace of around 90 minutes and a marathon pace of around 120 minutes. This means the average runner will be low on glycogen stores at around the halfway point during their marathon.

After consuming an energy gel, the blood absorbs the simple sugars, giving you a spike in energy. Through the blood, these sugars are then absorbed by your active muscles and organs, providing your body with a short energy boost.

Energy gels contain about 25g of carbohydrates per gel, with one gel providing about 45 minutes of running. However, taking two at a time does not provide 90 minutes of running. Instead, you’re likely to crash as your body attempts to process the sugar.

Some energy gels may contain other ingredients to boost your performance, such as electrolytes to replace lost minerals or caffeine to open up the blood vessels and speed up energy delivery. Some gels are fruit-flavoured, containing antioxidant-rich fruits like berries, which can help clear the muscles of waste products.

The perfect time to take an energy gel depends on the individual. Every runner absorbs and processes carbohydrates at a different rate. Some can feel the effect within three minutes, while for others, it might take up to 15.

As your body diverts blood from your stomach towards your active muscles, your absorption rate slows. Sometimes, your stomach shuts down completely, and this is, unfortunately, the most common cause of unwanted toilet stops during a run!

The most important rule is to take the gel before you need it, not as you feel yourself crashing or hitting the wall. We recommend you practise with energy gels throughout your training to ensure you know when and which energy gel to take. 

As your digestion process slows during your run, it’s important not to overload your stomach. Wait around 45-60 minutes between gels, or around 6-7 miles to ensure you don’t intake too much simple sugar at once. Likewise, consider alternating between caffeine and non-caffeine energy gels to ensure you don’t overload on caffeine. 

While energy gels are ideal for marathon runners, they’re not to everyone’s taste. Although usually water-based, they vary in consistency and intensity in taste.

With so many on the market, flavours vary from vanilla, chocolate, and coffee to lighter, fruity flavours like orange, apple, and berries. We recommend testing a few different brands and styles on practice runs to find the consistency and flavour right for you.